Add LOCAL_ prefix to non-UMA histogram macros.

base/metrics/field_trial.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // FieldTrial is a class for handling details of statistical experiments
 // performed by actual users in the field (i.e., in a shipped or beta product).
 // All code is called exclusively on the UI thread currently.
 //
 // The simplest example is an experiment to see whether one of two options
 // produces "better" results across our user population.  In that scenario, UMA
 // data is uploaded to aggregate the test results, and this FieldTrial class
 // manages the state of each such experiment (state == which option was
 // pseudo-randomly selected).
 //
 // States are typically generated randomly, either based on a one time
 // randomization (which will yield the same results, in terms of selecting
 // the client for a field trial or not, for every run of the program on a
 // given machine), or by a session randomization (generated each time the
 // application starts up, but held constant during the duration of the
 // process).
 
 //------------------------------------------------------------------------------
 // Example:  Suppose we have an experiment involving memory, such as determining
 // the impact of some pruning algorithm.
 // We assume that we already have a histogram of memory usage, such as:
 
-//   HISTOGRAM_COUNTS("Memory.RendererTotal", count);
+//   UMA_HISTOGRAM_COUNTS("Memory.RendererTotal", count);
 
 // Somewhere in main thread initialization code, we'd probably define an
 // instance of a FieldTrial, with code such as:
 
 // // FieldTrials are reference counted, and persist automagically until
 // // process teardown, courtesy of their automatic registration in
 // // FieldTrialList.
 // // Note: This field trial will run in Chrome instances compiled through
 // //       8 July, 2015, and after that all instances will be in "StandardMem".
 // scoped_refptr<base::FieldTrial> trial(
@@ skipping 440 matching lines @@
 
   // List of observers to be notified when a group is selected for a FieldTrial.
   scoped_refptr<ObserverListThreadSafe<Observer> > observer_list_;
 
   DISALLOW_COPY_AND_ASSIGN(FieldTrialList);
 };
 
 }  // namespace base
 
 #endif  // BASE_METRICS_FIELD_TRIAL_H_